Extinction and the U.S. Endangered Species Act Noah Greenwald Corresp., 1, Kieran F Suckling 2, Brett Hartl 3, Loyal Mehrhoff 4 1 Center for Biological Diversity, Portland, Oregon, United States 2 Center for Biological Diversity, Tucson, Arizona, United States 3 Center for Biological Diversity, Washington DC, United States 4 Center for Biological Diversity, Honolulu, Hawaii, United States Corresponding Author: Noah Greenwald Email address: ngreenwald@biologicaldiversity.org The United States Endangered Species Act is one of the strongest laws of any nation for preventing species extinction, but quantifying the Act s effectiveness has proven difficult. To provide one measure of effectiveness, we identified listed species that have gone extinct and used previously developed methods to update an estimate of the number of species extinctions prevented by the Act. To date, only five species have been confirmed extinct with another 22 possibly extinct following protection. Another 71 listed species are extinct or possibly extinct, but were last seen before protections were enacted, meaning the Act s protections never had the opportunity to save these species. In contrast, a total of 39 species have been fully recovered, including 23 in the last 10 years. We estimate the Endangered Species Act has prevented the extinction of roughly 465 species since passage in 1973, and has to date saved more than 99 percent of species under its protection.
1 Extinction and the U.S. Endangered Species Act 2 3 Noah Greenwald 1, Kieran F. Suckling 2, Brett Hartl 3, Loyal Mehrhoff 4 4 5 1 Center for Biological Diversity, Portland, Oregon, USA 6 2 Center for Biological Diversity, Tucson, Arizona, USA 7 3 Center for Biological Diversity, Washington DC, USA 8 4 Center for Biological Diversity, Honolulu, Hawaii, USA 9 10 Corresponding Author: 11 Noah Greenwald 1 12 PO Box 11374, Portland, OR 97211, USA 13 Email address: ngreenwald@biologicaldiversity.org 14 15 16 17 18 19 20 21 22 23
24 Abstract: 25 The United States Endangered Species Act is one of the strongest laws of any nation for 26 preventing species extinction, but quantifying the Act s effectiveness has proven difficult. To 27 provide one measure of effectiveness, we identified listed species that have gone extinct and 28 used previously developed methods to update an estimate of the number of species extinctions 29 prevented by the Act. To date, only five species have been confirmed extinct with another 22 30 possibly extinct following protection. Another 71 listed species are extinct or possibly extinct, 31 but were last seen before protections were enacted, meaning the Act s protections never had the 32 opportunity to save these species. In contrast, a total of 39 species have been fully recovered, 33 including 23 in the last 10 years. We estimate the Endangered Species Act has prevented the 34 extinction of roughly 465 species since passage in 1973, and has to date saved more than 99 35 percent of species under its protection. 36 37 38 39 40 41 42 43 44 45 46
47 Introduction 48 Passed in 1973, the U.S. Endangered Species Act (ESA) includes strong protections for listed 49 threatened and endangered species and has helped stabilize and recover hundreds of listed 50 species, such as the bald eagle and gray whale (Taylor, Suckling, & Rachlinski 2006; Schwartz, 51 2008; Suckling, Mehrhoff, Beam, & Hartl, 2016). In part because of its strong protections, the 52 ESA has engendered substantial opposition from industry lobby groups, who perceive the law as 53 threatening their profits and have been effective in generating opposition to species protections 54 among members of the U.S. Congress. One common refrain from opponents of the ESA in 55 Congress and elsewhere is that the law is a failure because only two percent of listed species 56 have been fully recovered and delisted (Hastings et. al., 2014). 57 58 The number of delistings, however, is a poor measure of the success of the ESA because most 59 species have not been protected for sufficient time such that they would be expected to have 60 recovered (Suckling et al., 2016). Short of recovery, a number of studies have found the ESA is 61 effectively stabilizing or improving the status of species, using both biennial status assessments 62 produced by the U.S. Fish and Wildlife Service for Congress and abundance trends (Male & 63 Bean, 2005; Taylor, Suckling, & Rachlinski 2006; Gibbs & Currie, 2012; Suckling et al., 2016). 64 65 In addition to recovering species, one of the primary purposes of the ESA is to prevent species 66 extinction. Previous studies indicate the ESA has been successful in this regard. As of 2008, the 67 ESA was estimated to have prevented the extinction of at least 227 species and the number of 68 species delisted due to recovery outnumbered the number of species delisted for extinction by 14 69 to 7 (Scott et al., 2006). In this study, we identified all ESA listed species that are extinct or
70 possibly extinct to quantify the number of species for which ESA protections have failed and use 71 these figures to update the estimated number of species extinctions prevented. This is the first 72 study to compile data on extinction of ESA listed species and provides an important measure of 73 one of the world s strongest conservation laws. 74 75 Methods 76 To identify extinct or possibly extinct ESA listed species, we examined the status of all 1,755 77 (species, subspecies and distinct population segments) U.S. listed or formerly listed species, 78 excluding species delisted based on a change in taxonomy or new information showing the 79 original listing to have been erroneous. We determined species to be extinct or possibly extinct 80 based on not being observed for at least ten years, the occurrence of adequate surveys of their 81 habitat, and presence of threats, such as destruction of habitat of the last known location or 82 presence of invasive species known to eliminate the species. 83 84 To differentiate extinct and possibly extinct species we relied on determinations by the U.S. Fish 85 and Wildlife Service, IUCN, species experts and other sources. In most cases, these 86 determinations were qualitative rather quantitative. Species were considered extinct if surveys 87 since the last observation were considered sufficient to conclude the species is highly likely to no 88 longer exist, and possibly extinct if surveys were conducted after the last observation, but were 89 not considered sufficient to conclude that extinction is highly likely (Butchart, Stattersfield, & 90 Brooks, 2006; Scott et al., 2008). 91
92 Source information included five-year reviews, listing rules and critical habitat designations by 93 the U.S. Fish and Wildlife Service (for aquatic and terrestrial species) or NOAA Fisheries (for 94 marine species), published and grey literature, personal communication with species experts, and 95 classifications and accounts by NatureServe, IUCN and the Hawaiian Plant Extinction 96 Prevention program. For each species, we identified year of listing, year last seen, NatureServe 97 and IUCN ranking, taxonomic group, and U.S. Fish and Wildlife Service region. For species last 98 seen after listing, we also searched for abundance estimates at time of listing in order to give a 99 sense of likelihood of survival regardless of ESA protection. 100 101 Following previously developed methods, we estimated the number of species extinctions 102 prevented by the ESA by assuming that listed threatened and endangered species have a 103 comparable extinction risk to IUCN endangered species, which was estimated as an average of 104 67 percent over 100 years (Mace, 1995; Schwartz, 1999; Scott et al., 2006). This figure was then 105 multiplied by the number of listed species and the proportion of a century in which species were 106 protected by the ESA, which was assumed to be 45 years (1973-2018) based on the year the law 107 was passed. This corresponds to the following formula: 108 109 Expected extinctions = (Spp. X 100 year Extinction Risk X Portion of a century with protection) 110 111 Results 112 We identified a total of 97 ESA listed species that are extinct (22) or possibly extinct (75). Of 113 these, we found 71 extinct or possibly extinct species were last observed before they were listed 114 under the ESA and thus are not relevant to determining the Act s success in preventing
115 extinction (Supplemental information, Table 1). These species were last seen an average of 24 116 years before protection was granted with a range of one to more than 80 years prior. 117 118 A total of 26 species were last seen after listing, of which five are confirmed extinct and 21 are 119 possibly extinct (Supplementary information, Table 2). On average, these species were last seen 120 13 years after listing with a range of 2-23 years. We were able to find an abundance estimate at 121 the time of listing for 19 of these species, ranging from one individual to more than 2,000 with 122 an average of 272. For those with a higher abundance, this was generally an estimate in some 123 cases based on very few sightings. 124 125 The distribution of extinct and possibly extinct species was non-random with 64 of the 97 126 species from Hawaii alone, followed by 18 from the southeast (Figure 1). This was also the case 127 for taxonomy. Forty of the 97 species were mollusks dominated by Hawaiian tree snails and 128 southeast mussels, followed by birds (18) and plants (17) (Figure 2). 129 130 We identified several other species that have been missing for more than 10 years, but for which 131 there has not been any effective surveys and thus classifying them as possibly extinct did not 132 seem appropriate, including two Hawaiian yellow-faced bees (Hylaeus facilis and Hylaeus 133 hilaris)(magnacca personal communication, 2018) and Fosberg s love grass (Eragrostis 134 fosbergii)(usfws, 2011). If indeed extinct, all three were lost prior to protection under the 135 ESA. 136
137 Including updated figures for number of listed species, time of protection and species 138 extinctions, we estimate the ESA has prevented the extinction of roughly 465 species in its 45 139 year history. Based on the number of confirmed extinctions following listing, we further 140 estimate that the ESA has to date prevented the extinction of more than 99 percent of species 141 under its protection. To date, a total of 39 species have been delisted for recovery compared to 142 five species that are extinct and 21 that are potentially extinct. 143 144 Discussion 145 The few number of listed species that have gone extinct following protection combined with an 146 estimated 465 species for which extinction was prevented demonstrate the ESA has achieved one 147 of its core purposes halting the loss of species. We will not attempt to catalogue them here, but 148 numerous individual examples provide further support for this conclusion. Well known species 149 like the California condor (Gymnogyps californianus), black-footed ferret (Mustela nigripes) and 150 Hawaiian monk seal (Neomonachus schauinslandi), as well as lesser known species like the 151 yellowfin madtom (Noturus flavipinnis), are but a few of the species that likely would have been 152 lost were it not for the ESA. 153 154 The madtom is a case in point. Wrongly presumed extinct when described in1969, individual 155 madtom were found in the Powell and Copper Rivers of Tennessee and the species was protected 156 under the ESA in 1977 (USFWS, 1977). Following protection, federal and state officials worked 157 with a non-governmental organization, Conservation Fisheries Inc., to discover additional 158 populations and repatriate the species to rivers and streams in its historic range and there are now
159 populations of the yellowfin madtom in five different watersheds (USFWS, 2012a). The history 160 of the ESA is replete with similar such stories. 161 162 The distribution of extinct or possibly extinct species largely tracks those regions with the 163 highest rates of species endangerment, including Hawaii and the Northern Marianas with 64 of 164 the 97 extinctions or possible extinctions, and the Southeast with 18 of the extinctions or possible 165 extinctions, mostly freshwater species. The fragility of Hawaii s endemic fauna to introduced 166 species and habitat destruction and high degree of species imperilment is well recognized (e.g. 167 Duffy & Kraus, 2006). Similarly, the extinction and endangerment of freshwater fauna in the 168 southeast is well documented (Benz & Collins, 1997). To avoid further extinctions, these areas 169 should be priorities for increased funding and effort. 170 171 Protection under the ESA came too late for the 71 species last seen prior to listing. This 172 highlights the need to move quickly to protect species. Indeed, Suckling, Slack & Nowicki 173 (2004) identified 42 species that went extinct while under consideration for protection. Since 174 that analysis was completed, the U.S. Fish and Wildlife Service has determined five additional 175 species did not qualify for protection because they were extinct, including the Tacoma pocket 176 gopher (Thomomys mazama tacomensis), Tatum Cave beetle (Pseudanophthalmus parvus), 177 Stephan s riffle beetle (Heterelmis stephani), beaverpond marstonia (Marstonia castor) and 178 Ozark pyrg (Marstonia ozarkensis), meaning there are now 47 species that have gone extinct 179 waiting for protection (USFWS, 2012b, 2016, 2017, 2018a). 180
181 The U.S. Fish and Wildlife Service currently faces a backlog of more than 500 species that have 182 been determined to potentially warrant protection, but which await a decision (USFWS, 2018b). 183 Under the ESA, decisions about protection for species are supposed to take two years, but on 184 average it has taken the Fish and Wildlife Service 12 years (Puckett, Kessler & Greenwald, 185 2016). Such lengthy wait times are certain to result in loss of further species and run counter to 186 the purpose of the statute. This problem can be addressed by streamlining the Service s process 187 for listing species, which has become increasingly cumbersome, and by increasing funding for 188 the listing program. 189 190 The loss of as many as 26 species after they were protected further highlights the need for 191 accelerating the rate of species listings, as most of these species were reduced to very low 192 numbers by the time they were protected, including at least eight that had dropped to fewer than 193 10 individuals. It also highlights the need to move quickly to save species when they have 194 dropped to such low levels. There are many examples of species both in the U.S. and 195 internationally that have been successfully recovered after dropping to very small numbers, but 196 this can only occur with fast, effective action, resources and in many cases luck. The Mauritius 197 kestrel (Falco punctatus), for example, was brought back from just two pairs (Cade & Jones, 198 1993) and the Hawaiian plant extinction prevention program, which focuses on saving plants 199 with fewer than 50 individuals, has rediscovered many species believed extinct, brought 177 200 species into cultivation, constructed fences to protect species from non-native predators and 201 reintroduced many species into the wild (Wood, 2012, http://www.pepphi.org/). 202
203 In this sense, all of the 97 ESA listed species that we identified as possibly extinct or extinct are 204 conservation failures. For 42 of these species, the law itself was too late because they were last 205 seen before the ESA was passed in 1973. But for others, there may have been time and we did 206 not act quickly enough. The dusky seaside sparrow is a case in point. Despite the species listing 207 in 1967 and noted population declines, birds were not brought into captivity until 1979, by which 208 time there were too few individuals for success and the species was lost (USFWS, 1990). 209 210 Our failure to provide sufficient resources for conservation continues to the present. As many as 211 27 species of Oahu tree snail (achatinella spp.) are extinct or possibly extinct, yet expenditures 212 for the species that still survive are inadequate to support minimal survey and captive 213 propagation efforts. Likewise, the Hawaiian plant extinction prevention program, which has 214 been so effective in saving species on the brink of extinction, is facing a budget cut of roughly 70 215 percent in 2019 (http://www.pepphi.org/), which very likely could mean the extinction of dozens 216 of plants that otherwise could be saved. Overall, Greenwald et al. (2016) estimate current 217 recovery funding is roughly three percent of estimated recovery costs from federal recovery 218 plans. We can save species from extinction, but it must be more of a priority for federal 219 spending. Nevertheless, despite funding shortfalls and the tragedy of these species having gone 220 extinct, the ESA has succeeded in preventing the extinction of the vast majority of listed species 221 and in this regard is a success. 222 223 224 225
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Figure 1(on next page) Extinction and taxonomic group Figure 1. Extinct or possibly extinct listed species by taxonomic group.
Reptiles Plants Mollusks Mammals Fish Birds Arthropods Amphibians Extinct Before Listing Extinct After Listing 0 5 10 15 20 25 30 35 Figure 1. Extinct or possibly extinct listed species by taxonomic group.
Figure 2(on next page) Extinctions by region Extinct or possibly extinct listed species by U.S. Fish and Wildlife Service Region.
Southwest Southeast Pacific Southwest Northeast Midwest Extinct Before Listing Extinct After Listing Pacific Islands Alaska 0 10 20 30 40 50 60 Figure 2. Extinct or possibly extinct listed species by U.S. Fish and Wildlife Service Region.